The present invention relates to apparatus for producing substantially equal irradiance at each point of a pre-selected area; to apparatus for converting visual data contained in transparencies or other visual media into electronic media; and to a system for integrating records contained in various media into a single useable media.
The modern medical practitioner has been blessed with a variety of new equipment capable of producing medical information in a variety of media. For example, computed tomography (CT) and magnetic resonance imaging (MRI) technologies produce information about the human body in a digital form that may later be displayed on a monitor or produced in a tangible form such as a negative for the treating physician to observe and to evaluate. With ultrasound imaging technology, the practitioner is able to view either a single snap shot taken at an instant in time or a movie produced from a series of such snap shots. With traditional X-ray equipment, the practitioner is provided with a view of the human body in the form of a negative, which can be observed and evaluated when the X-ray is displayed on a radiologist's lightbox. These are but some of the examples of the presently available devices that produce visual images for the medical practitioner to view and evaluate. Angiography, positron emission tomography (PET) scanning, and mammography are other examples.
While these devices produce vital medical imagery, they do so in a variety of different media. As noted above, the traditional X-ray is produced on a photographic negative. Most often, CT and MRI imagery are produced and stored as electronic media, although negative transparencies are also often produced from the electronic data. Images produced by ultrasound may be printed onto paper or may be captured in the form of a movie on videotape.
This broad variety of image storage media creates several problems. First, storage problems are presented for the institution where the information is gathered. Second, with the new imaging technologies, large numbers of images are created whereas in the past, perhaps only two or three X-rays would need to be accounted for by the record storage system. Third, the transfer of information in the form of the original images among medical personnel is hindered. Fourth, societal costs of the ill patient are increased. Examples of each of these problems may be readily given. Thus, X-ray negatives consume a considerable amount of often limited, expensive hospital floor space for storage of this form of tangible medical imagery. Other tangible imagery similarly use up large volumes of storage space. At large hospitals where thousands of these images are produced in short periods of time, filing of the images in the storage area so they can be found again may itself be a problem. Additionally, since other hard or paper copies of electronically produced imagery such as CT, ultrasound or the like are produced for viewing, the large numbers of images produced by these technologies exacerbates the storage problem.
Data transfer problems are increasing due to the ever-increasing specialization in the medical field. Medical records are being transferred from location to location both within and without a medical facility, with greater frequency.
Examples of data transfer problems include time delays inherent in the movement of tangible information from one location to another. Obviously these delays themselves slow communication between medical personnel. They also ma be additionally wasteful of time because they may keep busy a physician waiting for the information. The delays also may create a danger for a patient in need of rapid evaluation by an expert not present where the information is produced. Tangible media do not present the only communication problem, however. Information stored in electronic formats also presents problems because, presently, each manufacturer of CT, MRI, or other such imaging apparatus utilizes different electronic formats to acquire and store the data. Thus, even the data produced by these disparate techniques can present difficulties in providing a single storage system for electronically gathered technology; and because of that difficulty, utilization of the data after its acquisition can be difficult at any place other than the originating location.
Unnecessary, perhaps excessive, costs arise directly from the present system of medical record storage. For example, a patient may be retained in a hospital until a consulting physician, who may be an expert in a particular field, examines the particular medical imagery involved. Where the image media is an X-ray negative, the patient may be retained needlessly overnight while the X-ray is shipped to the consulting physician in a neighboring hospital, city or state or completely across the country. Not only may there be increased costs associated with retaining the patient in the hospital, but there are costs associated with the transfer of the important medical data in its tangible form such as postage expenses, handling costs, and reproduction costs if the medical images is copied and the copy sent rather than the original. Finally, a danger always exists that a vitally important medical image may be lost or misplaced during such shipments or storage.
Attempts have been made to deal with these problems. Thus, there exists apparatus capable of storing imagery produced in a digital format. Such systems do not well incorporate imagery that is produced in a non-electronic format in the first instance, such as X-rays, however. This stems from the fact that electronic reproductions of X-rays and the like have not been of a high enough quality for the evaluating physician to rely upon them. This inability to qualitatively reproduce the X-rays stems from an inability of present light sources to provide the proper backlighting to record the image on the transparency. The backlighting must, to provide a faithful, high quality reproduction, substantially equally irradiate each point of the transparency so that the data contained therein can be duly recorded. When too much light passes through one point relative to another, the information of the first point may be over emphasized and the information of the second point may be de-emphasized or lost entirely in the glare of the light passing through first point. Where the points form part of an X-ray, critical data important to a proper evaluation may be lost. Treating physicians are reluctant to rely on images for evaluation purposes when the image may have lost valuable or critical information in its reproduction from the original. Thus, equal irradiance is critical to high quality recording of X-rays, but not possible with present devices.
The above referred to systems rely upon digital transmission and replication of an image on a computer monitor, which is slow, however. Analogue transmission of the image would be faster; the technology in the medical area has shown a decisive digital trend, however, due, no doubt to the initial production of the electronic images in a digital format. Furthermore, because of its slowness, the digital systems provide little archiving capability to a medical institution. Because of these limitations, the digital systems presently available also provide limited education or training functions. This itself is critical in that many of the digital technologies are of a recent vintage and older practitioners are in need of training in the proper use of the data made available by digital imaging. Additionally, present day systems cannot provide true color displays of the data, which can aid in proper evaluation procedures, nor do they provide full motion. That is, with ultrasound and the like, motion studies are possible but since the present digital systems can take up to ninety seconds to transmit a single image from storage to a workstation, motion studies are essentially impossible to do.
This type of digital system is very expensive also, with costs often over one million dollars because of all of the necessary digital processing equipment. Analogue systems are quite inexpensive by comparison. Additional costs include the paper copies often produced of the digital images.
Another problem with the current image storage system is that there exists no single location where all of a patients records are stored. That is, X-rays may be in one location, an MR image may be in another, and the doctor's notes in still another. Gathering all of the records together is a tedious, time consuming task that could be improved if all of the images were stored in one location such as an electronic library. Storage of all records in a common medium including physician's notes, would completely eliminate this problem.
Thus, it has not been possible to design a single system capable of handling all medical imagery produced by the various apparatus now available. It would be desirable, therefore, to be able to convert tangible medical images originally in negative or positive views to an analogue electronic format and combined with digitally produced images such as that produced by CT, PET, MRI and the like devices in a common analogue format in a high density storage library such as that provided by optical disc technology at a reduced cost.